# On Rails — Aaron Patterson: Ractors, JIT Compilers, and Rewriting How Gems Install

> Source: <https://rubyonrails.org/2026/8/4/on-rails-aaron-patterson-ractors-jit-compilers-and-rewriting-how-gems-install>
> Published: 2026-08-04 00:00:00+00:00

In this episode of On Rails, Robby is joined by Aaron Patterson, better known online as Tenderlove, a senior staff engineer on Shopify’s Ruby infrastructure team and a longtime contributor to both Ruby and Rails Core. Aaron and Robby chat about how Ractors are finally bringing true multi-core parallelism to Ruby, the proposal Aaron has pitched to RubyGems.org for content addressable gems that could make bundle install dramatically faster, and the real reasons gems reach for native C extensions in the first place. They also have a candid conversation about how Aaron actually uses AI day to day, from digging through unfamiliar code at Shopify's scale to building a JPEG encoder almost entirely with Claude, and why he still can't quite bring himself to trust it the way he trusts a longtime teammate. Links TenderloveShopify Ractors RubyGems.org FFI